[SYCL][NewOffloadModel] Enforce default SYCL device library to use old offloading model

[YixingZhang007]

This pull request enforces the default SYCL device library to always be built with the old offloading model, regardless of which offloading model (new or old) is set as the default. This is implemented by adding --no-offload-new-driver to the device_compile_opts in libdevice/cmake/modules/SYCLLibdevice.cmake.
The motivation for this change is to address test failures in Config/kernel_from_file.cpp and SeparateCompile/test.cpp that occur when the new offloading model is enabled as the default. These failures happen because clang-offload-bundler does not support extracting libraries built with the new offloading model.

[YixingZhang007]

The modifications to set the new offloading model as default in this PR were directly copied from (#15121). These changes will be removed once CI confirms there are no regressions.

[YixingZhang007]

I do not think the current CI test failure is caused by the changes from this PR. I have also run the SYCL E2E tests with the new offloading model enabled as default together with my changes (the results can also be found at (https://github.com/intel/llvm/actions/runs/19120134686/job/54640222730; this is the CI from before removing the new offloading model changes from this PR). I haven't seen any regression, and the two tests Config/kernel_from_file.cpp and SeparateCompile/test.cpp are passing

[YixingZhang007]

I think this PR is waiting for review from @intel/llvm-reviewers-runtime. Thank you :)

[sarnex]

My review should be fine for runtime